1.) Greetings! Your library books are 1,000,000 years overdue.
2.) Request for Urgent Business Relationship! I am a Xandorphian prince whose assets have been seized, but if you send 1,000 kilograms of platinum to this planet, you will be able to release my funds. Act this solar cycle!
3.) SUMMONS FOR STANDBY JURY DUTY – Your planet has been selected as an alternate juror for the trial of Pangrob the Merciless. Please make your representatives available at the following Space/Time coordinates…
In Carl Sagan’s novel Contact, the first message received from Out There was a re-transmission of Adolf Hitler’s opening speech at the 1936 Summer Olympics in Berlin;
This was the first television signal powerful enough to escape Earth’s ionosphere, hence the aliens used it for their first contact message.
Must have loosened a few sphincters.
“Yoda of Borg am I. Hmmph! Assimilated you will be, yes. Futile, resistance is.”
Let me introduce to you our interplanetary reception party:
William Shatner
“We’re from the Intergalactic Government and we’re here to help.”
“H.G. Wells was right.”
“Greetings, brother and sister Roaches! How has this planet been treating you?”
FREE BIRD!!!
This annoyed me. I’m sure Sagan used it for the shock value, but Hugo Gernsback, publisher of magazines on Electrical Devices and one of the Founders of Science Fiction* was broadcasting TV signals from his station WRNY in New York from 1925 to 1934.
Other early TV pioneers were broadcasting at the same time. Some signals were sent over cables, but a lot of them were broadcast by radio waves.
These were mechanical TV, as opposed to cathode-ray systems, but that doesn’t mean the broadcasts were weaker (I haven’t seen any figures on signal strengths). But it could’ve been more meaningful if Sagan described the broadcast as from the Father of Science Fiction. (Other Image Orthicon broadcasts were regularly made well before Hitler’s 1936 broadcast, too)
All your base are belong to us.
For great justice,
Shodan
Fixed link:
Well now whether this is good or bad depends entirely on what they look like, doesn’t it?
In the movie Mars Attacks! it all turns ugly when a hippy releases a dove of peace, which spooks the alien envoy and it all kicks off. I’ve always thought it would have been a better twist of irony if the dove of peace had flown over the alien envoy and shat on him, and that’s the casus belli that leads to intergalactic Armageddon.
Hello, um…a…Meat…Er…Hows it going? 
“Hey Xhrrr, let’s try it to this star!”
“Okay! <giggle> The way the last one went poof was really funny! <hic>”
“Here goes! <untranslatable noise>”
“It’s not doing anything.”
“Remember? We had to wait a couple of <untranslatable> the last time?”
“Oh yeah.”
“<thump rattle>”
“Hey! Who left the translator on? We don’t want–”
Made me think of the story They’re Made out of Meat by Terry Bisson.
We’ve heard you taste like chicken.
Where is the nearest In and Out Burger?
Eat Lead Earthlings!
AT LAST! THIS TIMELINE HAS NO DOCTOR! EXTERMINATE!
or
At last! The Lost Colony of Earth. Umm, you do have anti-Base-Star defences up-and-running, yes? We have 33,um, no, 32 minutes…
Greetings brothers and sisters, we have come to take you to paradise where you will live with us for eternity indulging in pleasures or pursuits of your choice. Once you are safely onboard our ship, your planet and all other inhabiting organisms will be summarily destroyed and the constituent matter re-purposed for our life-sustaining machines.
Welcome! welcome, our aquatic marine mammal brothers and sisters!
562314…
562313…
562312…
562311…
“Mein Führer ! We have answered your call !”